This present disclosure relates to an apparatus and method for tuning or adjustment of air bag pressure venting prior to, during or after deployment of the air bag.
Air bag modules have become common in modern automobiles. An air bag module typically comprises an inflatable cushion and an inflator within a housing. The module is installed in a desired position within the vehicle, such as the steering wheel, the dashboard, the seat, the A-pillar, and the like. The inflatable cushion is stored in a folded position within the housing in fluid communication with an inflator. In response to an activation event or occurrence, a sensor provides a signal for activating the inflator. The inflator provides a supply of inflating gas to the cushion to inflate the cushion, deploying it from the housing into the vehicle.
This present disclosure provides for actively or dynamically adjusting the venting of inflation gas from a driver side or passenger side air bag cushion at any time prior to, during or after deployment of the air bag. This provides additional venting in advance of the deployment, additional venting during gas generation (cushion fill) or additional venting after the deployment. The additional venting is provided by holes or vent slots in a base plate and an inflator flange or a retainer plate. In the normal state (e.g., prior to activating the additional venting), the vent slots of the base plate and the inflator flange or retainer plate are blocked by a rotatable ring or rectilinearly slidable plate. When additional venting is requested, an actuator translates the rotatable ring or slidable plate to a position whereby vent slots in the rotatable ring or slidable plate at least partially align with the vent slots in the base plate and inflator flange or retainer plate. The additional vent slots are thus open for some of the inflation gas to exit the cushion.
In the case where no additional venting is requested, the rotatable ring or slidable plate is not translated, and the vent slots remain blocked and deployment of the air bag proceeds without additional venting.
As the inflation gases are in direct contact with the inflator flange to exit the additional vent slots, the invention has a cushion ring and cushion mouth larger in diameter than the inflator body. The rotatable ring or slidable plate could be made of self-lubricating plastic material to avoid corrosion or sticking of the mechanism.
Infinite adjustment of the vent slot size is achieved by means for translating the rotatable ring or slidable plate in controlled amounts. The controlled translation is accomplished with a linear actuator. Also, the controlled translation or limits on the translation can be accomplished prior to, during or after the deployment of the air bag with sensor inputs from the seat belt latch switch, seat-track position sensor, occupant weight sensor, etc. A first linear actuator can be used to adjust stops on the rotatable ring or slidable plate prior to the deployment, based upon, for example, seat belt usage, seat track position, occupant size, etc. A second actuator can initiate translation of the rotatable ring or slidable plate to the stops during or after deployment of the airbag as necessary. This provides two levels of venting during the deployment, with the second level of venting being infinitely adjustable prior to deployment.